add pull request template

.github/pull_request_template.md

@@ -0,0 +1,3 @@
+**By submitting this pull request, I promise I have read the [contribution guidelines](https://github.com/sindresorhus/awesome-nodejs/blob/master/contributing.md) twice and ensured my submission follows it. I realize not doing so wastes the maintainers' time that they could have spent making the world better. 🖖**
+
+⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆